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denoland-deno/core/runtime.rs

2272 lines
71 KiB
Rust

// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
use rusty_v8 as v8;
use crate::bindings;
use crate::error::attach_handle_to_error;
use crate::error::generic_error;
use crate::error::AnyError;
use crate::error::ErrWithV8Handle;
use crate::error::JsError;
use crate::inspector::JsRuntimeInspector;
use crate::module_specifier::ModuleSpecifier;
use crate::modules::ModuleId;
use crate::modules::ModuleLoadId;
use crate::modules::ModuleLoader;
use crate::modules::ModuleMap;
use crate::modules::NoopModuleLoader;
use crate::ops::*;
use crate::Extension;
use crate::OpMiddlewareFn;
use crate::OpPayload;
use crate::OpResult;
use crate::OpState;
use crate::PromiseId;
use futures::channel::oneshot;
use futures::future::poll_fn;
use futures::future::FutureExt;
use futures::stream::FuturesUnordered;
use futures::stream::StreamExt;
use futures::task::AtomicWaker;
use futures::Future;
use std::any::Any;
use std::cell::RefCell;
use std::collections::HashMap;
use std::convert::TryFrom;
use std::ffi::c_void;
use std::mem::forget;
use std::option::Option;
use std::pin::Pin;
use std::rc::Rc;
use std::sync::Arc;
use std::sync::Mutex;
use std::sync::Once;
use std::task::Context;
use std::task::Poll;
type PendingOpFuture = Pin<Box<dyn Future<Output = (PromiseId, OpResult)>>>;
pub enum Snapshot {
Static(&'static [u8]),
JustCreated(v8::StartupData),
Boxed(Box<[u8]>),
}
pub type JsErrorCreateFn = dyn Fn(JsError) -> AnyError;
pub type GetErrorClassFn =
&'static dyn for<'e> Fn(&'e AnyError) -> &'static str;
/// Objects that need to live as long as the isolate
#[derive(Default)]
struct IsolateAllocations {
near_heap_limit_callback_data:
Option<(Box<RefCell<dyn Any>>, v8::NearHeapLimitCallback)>,
}
/// A single execution context of JavaScript. Corresponds roughly to the "Web
/// Worker" concept in the DOM. A JsRuntime is a Future that can be used with
/// an event loop (Tokio, async_std).
////
/// The JsRuntime future completes when there is an error or when all
/// pending ops have completed.
///
/// Pending ops are created in JavaScript by calling Deno.core.opAsync(), and in Rust
/// by implementing an async function that takes a serde::Deserialize "control argument"
/// and an optional zero copy buffer, each async Op is tied to a Promise in JavaScript.
pub struct JsRuntime {
// This is an Option<OwnedIsolate> instead of just OwnedIsolate to workaround
// a safety issue with SnapshotCreator. See JsRuntime::drop.
v8_isolate: Option<v8::OwnedIsolate>,
// This is an Option<Box<JsRuntimeInspector> instead of just Box<JsRuntimeInspector>
// to workaround a safety issue. See JsRuntime::drop.
inspector: Option<Box<JsRuntimeInspector>>,
snapshot_creator: Option<v8::SnapshotCreator>,
has_snapshotted: bool,
allocations: IsolateAllocations,
extensions: Vec<Extension>,
}
struct DynImportModEvaluate {
load_id: ModuleLoadId,
module_id: ModuleId,
promise: v8::Global<v8::Promise>,
module: v8::Global<v8::Module>,
}
struct ModEvaluate {
promise: v8::Global<v8::Promise>,
sender: oneshot::Sender<Result<(), AnyError>>,
}
pub struct CrossIsolateStore<T>(Arc<Mutex<CrossIsolateStoreInner<T>>>);
struct CrossIsolateStoreInner<T> {
map: HashMap<u32, T>,
last_id: u32,
}
impl<T> CrossIsolateStore<T> {
pub(crate) fn insert(&self, value: T) -> u32 {
let mut store = self.0.lock().unwrap();
let last_id = store.last_id;
store.map.insert(last_id, value);
store.last_id += 1;
last_id
}
pub(crate) fn take(&self, id: u32) -> Option<T> {
let mut store = self.0.lock().unwrap();
store.map.remove(&id)
}
}
impl<T> Default for CrossIsolateStore<T> {
fn default() -> Self {
CrossIsolateStore(Arc::new(Mutex::new(CrossIsolateStoreInner {
map: Default::default(),
last_id: 0,
})))
}
}
impl<T> Clone for CrossIsolateStore<T> {
fn clone(&self) -> Self {
Self(self.0.clone())
}
}
pub type SharedArrayBufferStore =
CrossIsolateStore<v8::SharedRef<v8::BackingStore>>;
pub type CompiledWasmModuleStore = CrossIsolateStore<v8::CompiledWasmModule>;
/// Internal state for JsRuntime which is stored in one of v8::Isolate's
/// embedder slots.
pub(crate) struct JsRuntimeState {
pub global_context: Option<v8::Global<v8::Context>>,
pub(crate) js_recv_cb: Option<v8::Global<v8::Function>>,
pub(crate) js_macrotask_cb: Option<v8::Global<v8::Function>>,
pub(crate) js_wasm_streaming_cb: Option<v8::Global<v8::Function>>,
pub(crate) pending_promise_exceptions:
HashMap<v8::Global<v8::Promise>, v8::Global<v8::Value>>,
pending_dyn_mod_evaluate: Vec<DynImportModEvaluate>,
pending_mod_evaluate: Option<ModEvaluate>,
/// A counter used to delay our dynamic import deadlock detection by one spin
/// of the event loop.
dyn_module_evaluate_idle_counter: u32,
pub(crate) js_error_create_fn: Rc<JsErrorCreateFn>,
pub(crate) pending_ops: FuturesUnordered<PendingOpFuture>,
pub(crate) pending_unref_ops: FuturesUnordered<PendingOpFuture>,
pub(crate) have_unpolled_ops: bool,
pub(crate) op_state: Rc<RefCell<OpState>>,
pub(crate) shared_array_buffer_store: Option<SharedArrayBufferStore>,
pub(crate) compiled_wasm_module_store: Option<CompiledWasmModuleStore>,
waker: AtomicWaker,
}
impl Drop for JsRuntime {
fn drop(&mut self) {
// The Isolate object must outlive the Inspector object, but this is
// currently not enforced by the type system.
self.inspector.take();
if let Some(creator) = self.snapshot_creator.take() {
// TODO(ry): in rusty_v8, `SnapShotCreator::get_owned_isolate()` returns
// a `struct OwnedIsolate` which is not actually owned, hence the need
// here to leak the `OwnedIsolate` in order to avoid a double free and
// the segfault that it causes.
let v8_isolate = self.v8_isolate.take().unwrap();
forget(v8_isolate);
// TODO(ry) V8 has a strange assert which prevents a SnapshotCreator from
// being deallocated if it hasn't created a snapshot yet.
// https://github.com/v8/v8/blob/73212783fbd534fac76cc4b66aac899c13f71fc8/src/api.cc#L603
// If that assert is removed, this if guard could be removed.
// WARNING: There may be false positive LSAN errors here.
if self.has_snapshotted {
drop(creator);
}
}
}
}
fn v8_init(v8_platform: Option<v8::SharedRef<v8::Platform>>) {
// Include 10MB ICU data file.
#[repr(C, align(16))]
struct IcuData([u8; 10144432]);
static ICU_DATA: IcuData = IcuData(*include_bytes!("icudtl.dat"));
v8::icu::set_common_data_69(&ICU_DATA.0).unwrap();
let v8_platform = v8_platform
.unwrap_or_else(|| v8::new_default_platform(0, false).make_shared());
v8::V8::initialize_platform(v8_platform);
v8::V8::initialize();
let flags = concat!(
" --experimental-wasm-threads",
" --wasm-test-streaming",
" --harmony-import-assertions",
" --no-validate-asm",
);
v8::V8::set_flags_from_string(flags);
}
#[derive(Default)]
pub struct RuntimeOptions {
/// Allows a callback to be set whenever a V8 exception is made. This allows
/// the caller to wrap the JsError into an error. By default this callback
/// is set to `JsError::create()`.
pub js_error_create_fn: Option<Rc<JsErrorCreateFn>>,
/// Allows to map error type to a string "class" used to represent
/// error in JavaScript.
pub get_error_class_fn: Option<GetErrorClassFn>,
/// Implementation of `ModuleLoader` which will be
/// called when V8 requests to load ES modules.
///
/// If not provided runtime will error if code being
/// executed tries to load modules.
pub module_loader: Option<Rc<dyn ModuleLoader>>,
/// JsRuntime extensions, not to be confused with ES modules
/// these are sets of ops and other JS code to be initialized.
pub extensions: Vec<Extension>,
/// V8 snapshot that should be loaded on startup.
///
/// Currently can't be used with `will_snapshot`.
pub startup_snapshot: Option<Snapshot>,
/// Prepare runtime to take snapshot of loaded code.
///
/// Currently can't be used with `startup_snapshot`.
pub will_snapshot: bool,
/// Isolate creation parameters.
pub create_params: Option<v8::CreateParams>,
/// V8 platform instance to use. Used when Deno initializes V8
/// (which it only does once), otherwise it's silenty dropped.
pub v8_platform: Option<v8::SharedRef<v8::Platform>>,
/// The store to use for transferring SharedArrayBuffers between isolates.
/// If multiple isolates should have the possibility of sharing
/// SharedArrayBuffers, they should use the same [SharedArrayBufferStore]. If
/// no [SharedArrayBufferStore] is specified, SharedArrayBuffer can not be
/// serialized.
pub shared_array_buffer_store: Option<SharedArrayBufferStore>,
/// The store to use for transferring `WebAssembly.Module` objects between
/// isolates.
/// If multiple isolates should have the possibility of sharing
/// `WebAssembly.Module` objects, they should use the same
/// [CompiledWasmModuleStore]. If no [CompiledWasmModuleStore] is specified,
/// `WebAssembly.Module` objects cannot be serialized.
pub compiled_wasm_module_store: Option<CompiledWasmModuleStore>,
}
impl JsRuntime {
/// Only constructor, configuration is done through `options`.
pub fn new(mut options: RuntimeOptions) -> Self {
let v8_platform = options.v8_platform.take();
static DENO_INIT: Once = Once::new();
DENO_INIT.call_once(move || v8_init(v8_platform));
let has_startup_snapshot = options.startup_snapshot.is_some();
let global_context;
let (mut isolate, maybe_snapshot_creator) = if options.will_snapshot {
// TODO(ry) Support loading snapshots before snapshotting.
assert!(options.startup_snapshot.is_none());
let mut creator =
v8::SnapshotCreator::new(Some(&bindings::EXTERNAL_REFERENCES));
let isolate = unsafe { creator.get_owned_isolate() };
let mut isolate = JsRuntime::setup_isolate(isolate);
{
let scope = &mut v8::HandleScope::new(&mut isolate);
let context = bindings::initialize_context(scope);
global_context = v8::Global::new(scope, context);
creator.set_default_context(context);
}
(isolate, Some(creator))
} else {
let mut params = options
.create_params
.take()
.unwrap_or_else(v8::Isolate::create_params)
.external_references(&**bindings::EXTERNAL_REFERENCES);
let snapshot_loaded = if let Some(snapshot) = options.startup_snapshot {
params = match snapshot {
Snapshot::Static(data) => params.snapshot_blob(data),
Snapshot::JustCreated(data) => params.snapshot_blob(data),
Snapshot::Boxed(data) => params.snapshot_blob(data),
};
true
} else {
false
};
let isolate = v8::Isolate::new(params);
let mut isolate = JsRuntime::setup_isolate(isolate);
{
let scope = &mut v8::HandleScope::new(&mut isolate);
let context = if snapshot_loaded {
v8::Context::new(scope)
} else {
// If no snapshot is provided, we initialize the context with empty
// main source code and source maps.
bindings::initialize_context(scope)
};
global_context = v8::Global::new(scope, context);
}
(isolate, None)
};
let inspector =
JsRuntimeInspector::new(&mut isolate, global_context.clone());
let loader = options
.module_loader
.unwrap_or_else(|| Rc::new(NoopModuleLoader));
let js_error_create_fn = options
.js_error_create_fn
.unwrap_or_else(|| Rc::new(JsError::create));
let mut op_state = OpState::new();
if let Some(get_error_class_fn) = options.get_error_class_fn {
op_state.get_error_class_fn = get_error_class_fn;
}
let op_state = Rc::new(RefCell::new(op_state));
isolate.set_slot(Rc::new(RefCell::new(JsRuntimeState {
global_context: Some(global_context),
pending_promise_exceptions: HashMap::new(),
pending_dyn_mod_evaluate: vec![],
pending_mod_evaluate: None,
dyn_module_evaluate_idle_counter: 0,
js_recv_cb: None,
js_macrotask_cb: None,
js_wasm_streaming_cb: None,
js_error_create_fn,
pending_ops: FuturesUnordered::new(),
pending_unref_ops: FuturesUnordered::new(),
shared_array_buffer_store: options.shared_array_buffer_store,
compiled_wasm_module_store: options.compiled_wasm_module_store,
op_state: op_state.clone(),
have_unpolled_ops: false,
waker: AtomicWaker::new(),
})));
let module_map = ModuleMap::new(loader, op_state);
isolate.set_slot(Rc::new(RefCell::new(module_map)));
// Add builtins extension
options
.extensions
.insert(0, crate::ops_builtin::init_builtins());
let mut js_runtime = Self {
v8_isolate: Some(isolate),
inspector: Some(inspector),
snapshot_creator: maybe_snapshot_creator,
has_snapshotted: false,
allocations: IsolateAllocations::default(),
extensions: options.extensions,
};
// TODO(@AaronO): diff extensions inited in snapshot and those provided
// for now we assume that snapshot and extensions always match
if !has_startup_snapshot {
js_runtime.init_extension_js().unwrap();
}
// Init extension ops
js_runtime.init_extension_ops().unwrap();
js_runtime.sync_ops_cache();
// Init async ops callback
js_runtime.init_recv_cb();
js_runtime
}
pub fn global_context(&mut self) -> v8::Global<v8::Context> {
let state = Self::state(self.v8_isolate());
let state = state.borrow();
state.global_context.clone().unwrap()
}
pub fn v8_isolate(&mut self) -> &mut v8::OwnedIsolate {
self.v8_isolate.as_mut().unwrap()
}
pub fn inspector(&mut self) -> &mut Box<JsRuntimeInspector> {
self.inspector.as_mut().unwrap()
}
pub fn handle_scope(&mut self) -> v8::HandleScope {
let context = self.global_context();
v8::HandleScope::with_context(self.v8_isolate(), context)
}
fn setup_isolate(mut isolate: v8::OwnedIsolate) -> v8::OwnedIsolate {
isolate.set_capture_stack_trace_for_uncaught_exceptions(true, 10);
isolate.set_promise_reject_callback(bindings::promise_reject_callback);
isolate.set_host_initialize_import_meta_object_callback(
bindings::host_initialize_import_meta_object_callback,
);
isolate.set_host_import_module_dynamically_callback(
bindings::host_import_module_dynamically_callback,
);
isolate
}
pub(crate) fn state(isolate: &v8::Isolate) -> Rc<RefCell<JsRuntimeState>> {
let s = isolate.get_slot::<Rc<RefCell<JsRuntimeState>>>().unwrap();
s.clone()
}
pub(crate) fn module_map(isolate: &v8::Isolate) -> Rc<RefCell<ModuleMap>> {
let module_map = isolate.get_slot::<Rc<RefCell<ModuleMap>>>().unwrap();
module_map.clone()
}
/// Initializes JS of provided Extensions
fn init_extension_js(&mut self) -> Result<(), AnyError> {
// Take extensions to avoid double-borrow
let mut extensions: Vec<Extension> = std::mem::take(&mut self.extensions);
for m in extensions.iter_mut() {
let js_files = m.init_js();
for (filename, source) in js_files {
let source = source()?;
// TODO(@AaronO): use JsRuntime::execute_static() here to move src off heap
self.execute_script(filename, &source)?;
}
}
// Restore extensions
self.extensions = extensions;
Ok(())
}
/// Initializes ops of provided Extensions
fn init_extension_ops(&mut self) -> Result<(), AnyError> {
let op_state = self.op_state();
// Take extensions to avoid double-borrow
let mut extensions: Vec<Extension> = std::mem::take(&mut self.extensions);
// Middleware
let middleware: Vec<Box<OpMiddlewareFn>> = extensions
.iter_mut()
.filter_map(|e| e.init_middleware())
.collect();
// macroware wraps an opfn in all the middleware
let macroware =
move |name, opfn| middleware.iter().fold(opfn, |opfn, m| m(name, opfn));
// Register ops
for e in extensions.iter_mut() {
e.init_state(&mut op_state.borrow_mut())?;
// Register each op after middlewaring it
let ops = e.init_ops().unwrap_or_default();
for (name, opfn) in ops {
self.register_op(name, macroware(name, opfn));
}
}
// Sync ops cache
self.sync_ops_cache();
// Restore extensions
self.extensions = extensions;
Ok(())
}
/// Grabs a reference to core.js' opresolve
fn init_recv_cb(&mut self) {
let scope = &mut self.handle_scope();
// Get Deno.core.opresolve
let code = v8::String::new(scope, "Deno.core.opresolve").unwrap();
let script = v8::Script::compile(scope, code, None).unwrap();
let v8_value = script.run(scope).unwrap();
// Put global handle in state.js_recv_cb
let state_rc = JsRuntime::state(scope);
let mut state = state_rc.borrow_mut();
let cb = v8::Local::<v8::Function>::try_from(v8_value).unwrap();
state.js_recv_cb.replace(v8::Global::new(scope, cb));
}
/// Ensures core.js has the latest op-name to op-id mappings
pub fn sync_ops_cache(&mut self) {
self
.execute_script("<anon>", "Deno.core.syncOpsCache()")
.unwrap();
}
/// Returns the runtime's op state, which can be used to maintain ops
/// and access resources between op calls.
pub fn op_state(&mut self) -> Rc<RefCell<OpState>> {
let state_rc = Self::state(self.v8_isolate());
let state = state_rc.borrow();
state.op_state.clone()
}
/// Executes traditional JavaScript code (traditional = not ES modules).
///
/// The execution takes place on the current global context, so it is possible
/// to maintain local JS state and invoke this method multiple times.
///
/// `name` can be a filepath or any other string, eg.
///
/// - "/some/file/path.js"
/// - "<anon>"
/// - "[native code]"
///
/// The same `name` value can be used for multiple executions.
///
/// `AnyError` can be downcast to a type that exposes additional information
/// about the V8 exception. By default this type is `JsError`, however it may
/// be a different type if `RuntimeOptions::js_error_create_fn` has been set.
pub fn execute_script(
&mut self,
name: &str,
source_code: &str,
) -> Result<v8::Global<v8::Value>, AnyError> {
let scope = &mut self.handle_scope();
let source = v8::String::new(scope, source_code).unwrap();
let name = v8::String::new(scope, name).unwrap();
let origin = bindings::script_origin(scope, name);
let tc_scope = &mut v8::TryCatch::new(scope);
let script = match v8::Script::compile(tc_scope, source, Some(&origin)) {
Some(script) => script,
None => {
let exception = tc_scope.exception().unwrap();
return exception_to_err_result(tc_scope, exception, false);
}
};
match script.run(tc_scope) {
Some(value) => {
let value_handle = v8::Global::new(tc_scope, value);
Ok(value_handle)
}
None => {
assert!(tc_scope.has_caught());
let exception = tc_scope.exception().unwrap();
exception_to_err_result(tc_scope, exception, false)
}
}
}
/// Takes a snapshot. The isolate should have been created with will_snapshot
/// set to true.
///
/// `AnyError` can be downcast to a type that exposes additional information
/// about the V8 exception. By default this type is `JsError`, however it may
/// be a different type if `RuntimeOptions::js_error_create_fn` has been set.
pub fn snapshot(&mut self) -> v8::StartupData {
assert!(self.snapshot_creator.is_some());
let state = Self::state(self.v8_isolate());
// Note: create_blob() method must not be called from within a HandleScope.
// TODO(piscisaureus): The rusty_v8 type system should enforce this.
state.borrow_mut().global_context.take();
self.inspector.take();
// Overwrite existing ModuleMap to drop v8::Global handles
self
.v8_isolate()
.set_slot(Rc::new(RefCell::new(ModuleMap::new(
Rc::new(NoopModuleLoader),
state.borrow().op_state.clone(),
))));
// Drop other v8::Global handles before snapshotting
std::mem::take(&mut state.borrow_mut().js_recv_cb);
let snapshot_creator = self.snapshot_creator.as_mut().unwrap();
let snapshot = snapshot_creator
.create_blob(v8::FunctionCodeHandling::Keep)
.unwrap();
self.has_snapshotted = true;
snapshot
}
/// Registers an op that can be called from JavaScript.
///
/// The _op_ mechanism allows to expose Rust functions to the JS runtime,
/// which can be called using the provided `name`.
///
/// This function provides byte-level bindings. To pass data via JSON, the
/// following functions can be passed as an argument for `op_fn`:
/// * [op_sync()](fn.op_sync.html)
/// * [op_async()](fn.op_async.html)
pub fn register_op<F>(&mut self, name: &str, op_fn: F) -> OpId
where
F: Fn(Rc<RefCell<OpState>>, OpPayload) -> Op + 'static,
{
Self::state(self.v8_isolate())
.borrow_mut()
.op_state
.borrow_mut()
.op_table
.register_op(name, op_fn)
}
/// Registers a callback on the isolate when the memory limits are approached.
/// Use this to prevent V8 from crashing the process when reaching the limit.
///
/// Calls the closure with the current heap limit and the initial heap limit.
/// The return value of the closure is set as the new limit.
pub fn add_near_heap_limit_callback<C>(&mut self, cb: C)
where
C: FnMut(usize, usize) -> usize + 'static,
{
let boxed_cb = Box::new(RefCell::new(cb));
let data = boxed_cb.as_ptr() as *mut c_void;
let prev = self
.allocations
.near_heap_limit_callback_data
.replace((boxed_cb, near_heap_limit_callback::<C>));
if let Some((_, prev_cb)) = prev {
self
.v8_isolate()
.remove_near_heap_limit_callback(prev_cb, 0);
}
self
.v8_isolate()
.add_near_heap_limit_callback(near_heap_limit_callback::<C>, data);
}
pub fn remove_near_heap_limit_callback(&mut self, heap_limit: usize) {
if let Some((_, cb)) = self.allocations.near_heap_limit_callback_data.take()
{
self
.v8_isolate()
.remove_near_heap_limit_callback(cb, heap_limit);
}
}
fn pump_v8_message_loop(&mut self) {
let scope = &mut self.handle_scope();
while v8::Platform::pump_message_loop(
&v8::V8::get_current_platform(),
scope,
false, // don't block if there are no tasks
) {
// do nothing
}
scope.perform_microtask_checkpoint();
}
/// Waits for the given value to resolve while polling the event loop.
///
/// This future resolves when either the value is resolved or the event loop runs to
/// completion.
pub async fn resolve_value(
&mut self,
global: v8::Global<v8::Value>,
) -> Result<v8::Global<v8::Value>, AnyError> {
poll_fn(|cx| {
let state = self.poll_event_loop(cx, false);
let mut scope = self.handle_scope();
let local = v8::Local::<v8::Value>::new(&mut scope, &global);
if let Ok(promise) = v8::Local::<v8::Promise>::try_from(local) {
match promise.state() {
v8::PromiseState::Pending => match state {
Poll::Ready(Ok(_)) => {
let msg = "Promise resolution is still pending but the event loop has already resolved.";
Poll::Ready(Err(generic_error(msg)))
},
Poll::Ready(Err(e)) => Poll::Ready(Err(e)),
Poll::Pending => Poll::Pending,
},
v8::PromiseState::Fulfilled => {
let value = promise.result(&mut scope);
let value_handle = v8::Global::new(&mut scope, value);
Poll::Ready(Ok(value_handle))
}
v8::PromiseState::Rejected => {
let exception = promise.result(&mut scope);
Poll::Ready(exception_to_err_result(&mut scope, exception, false))
}
}
} else {
let value_handle = v8::Global::new(&mut scope, local);
Poll::Ready(Ok(value_handle))
}
})
.await
}
/// Runs event loop to completion
///
/// This future resolves when:
/// - there are no more pending dynamic imports
/// - there are no more pending ops
/// - there are no more active inspector sessions (only if `wait_for_inspector` is set to true)
pub async fn run_event_loop(
&mut self,
wait_for_inspector: bool,
) -> Result<(), AnyError> {
poll_fn(|cx| self.poll_event_loop(cx, wait_for_inspector)).await
}
/// Runs a single tick of event loop
///
/// If `wait_for_inspector` is set to true event loop
/// will return `Poll::Pending` if there are active inspector sessions.
pub fn poll_event_loop(
&mut self,
cx: &mut Context,
wait_for_inspector: bool,
) -> Poll<Result<(), AnyError>> {
// We always poll the inspector first
let _ = self.inspector().poll_unpin(cx);
let state_rc = Self::state(self.v8_isolate());
let module_map_rc = Self::module_map(self.v8_isolate());
{
let state = state_rc.borrow();
state.waker.register(cx.waker());
}
self.pump_v8_message_loop();
// Ops
{
let async_responses = self.poll_pending_ops(cx);
self.async_op_response(async_responses)?;
self.drain_macrotasks()?;
self.check_promise_exceptions()?;
}
// Dynamic module loading - ie. modules loaded using "import()"
{
let poll_imports = self.prepare_dyn_imports(cx)?;
assert!(poll_imports.is_ready());
let poll_imports = self.poll_dyn_imports(cx)?;
assert!(poll_imports.is_ready());
self.evaluate_dyn_imports();
self.check_promise_exceptions()?;
}
// Top level module
self.evaluate_pending_module();
let mut state = state_rc.borrow_mut();
let module_map = module_map_rc.borrow();
let has_pending_ops = !state.pending_ops.is_empty();
let has_pending_dyn_imports = module_map.has_pending_dynamic_imports();
let has_pending_dyn_module_evaluation =
!state.pending_dyn_mod_evaluate.is_empty();
let has_pending_module_evaluation = state.pending_mod_evaluate.is_some();
let has_pending_background_tasks =
self.v8_isolate().has_pending_background_tasks();
let inspector_has_active_sessions = self
.inspector
.as_ref()
.map(|i| i.has_active_sessions())
.unwrap_or(false);
if !has_pending_ops
&& !has_pending_dyn_imports
&& !has_pending_dyn_module_evaluation
&& !has_pending_module_evaluation
&& !has_pending_background_tasks
{
if wait_for_inspector && inspector_has_active_sessions {
return Poll::Pending;
}
return Poll::Ready(Ok(()));
}
// Check if more async ops have been dispatched
// during this turn of event loop.
// If there are any pending background tasks, we also wake the runtime to
// make sure we don't miss them.
// TODO(andreubotella) The event loop will spin as long as there are pending
// background tasks. We should look into having V8 notify us when a
// background task is done.
if state.have_unpolled_ops || has_pending_background_tasks {
state.waker.wake();
}
if has_pending_module_evaluation {
if has_pending_ops
|| has_pending_dyn_imports
|| has_pending_dyn_module_evaluation
|| has_pending_background_tasks
{
// pass, will be polled again
} else {
let msg = "Module evaluation is still pending but there are no pending ops or dynamic imports. This situation is often caused by unresolved promise.";
return Poll::Ready(Err(generic_error(msg)));
}
}
if has_pending_dyn_module_evaluation {
if has_pending_ops
|| has_pending_dyn_imports
|| has_pending_background_tasks
{
// pass, will be polled again
} else if state.dyn_module_evaluate_idle_counter >= 1 {
let mut msg = "Dynamically imported module evaluation is still pending but there are no pending ops. This situation is often caused by unresolved promise.
Pending dynamic modules:\n".to_string();
for pending_evaluate in &state.pending_dyn_mod_evaluate {
let module_info = module_map
.get_info_by_id(&pending_evaluate.module_id)
.unwrap();
msg.push_str(&format!("- {}", module_info.name.as_str()));
}
return Poll::Ready(Err(generic_error(msg)));
} else {
// Delay the above error by one spin of the event loop. A dynamic import
// evaluation may complete during this, in which case the counter will
// reset.
state.dyn_module_evaluate_idle_counter += 1;
state.waker.wake();
}
}
Poll::Pending
}
}
extern "C" fn near_heap_limit_callback<F>(
data: *mut c_void,
current_heap_limit: usize,
initial_heap_limit: usize,
) -> usize
where
F: FnMut(usize, usize) -> usize,
{
let callback = unsafe { &mut *(data as *mut F) };
callback(current_heap_limit, initial_heap_limit)
}
impl JsRuntimeState {
/// Called by `bindings::host_import_module_dynamically_callback`
/// after initiating new dynamic import load.
pub fn notify_new_dynamic_import(&mut self) {
// Notify event loop to poll again soon.
self.waker.wake();
}
}
pub(crate) fn exception_to_err_result<'s, T>(
scope: &mut v8::HandleScope<'s>,
exception: v8::Local<v8::Value>,
in_promise: bool,
) -> Result<T, AnyError> {
let is_terminating_exception = scope.is_execution_terminating();
let mut exception = exception;
if is_terminating_exception {
// TerminateExecution was called. Cancel exception termination so that the
// exception can be created..
scope.cancel_terminate_execution();
// Maybe make a new exception object.
if exception.is_null_or_undefined() {
let message = v8::String::new(scope, "execution terminated").unwrap();
exception = v8::Exception::error(scope, message);
}
}
let mut js_error = JsError::from_v8_exception(scope, exception);
if in_promise {
js_error.message = format!(
"Uncaught (in promise) {}",
js_error.message.trim_start_matches("Uncaught ")
);
}
let state_rc = JsRuntime::state(scope);
let state = state_rc.borrow();
let js_error = (state.js_error_create_fn)(js_error);
if is_terminating_exception {
// Re-enable exception termination.
scope.terminate_execution();
}
Err(js_error)
}
// Related to module loading
impl JsRuntime {
pub(crate) fn instantiate_module(
&mut self,
id: ModuleId,
) -> Result<(), AnyError> {
let module_map_rc = Self::module_map(self.v8_isolate());
let scope = &mut self.handle_scope();
let tc_scope = &mut v8::TryCatch::new(scope);
let module = module_map_rc
.borrow()
.get_handle(id)
.map(|handle| v8::Local::new(tc_scope, handle))
.expect("ModuleInfo not found");
if module.get_status() == v8::ModuleStatus::Errored {
let exception = module.get_exception();
let err = exception_to_err_result(tc_scope, exception, false)
.map_err(|err| attach_handle_to_error(tc_scope, err, exception));
return err;
}
// IMPORTANT: No borrows to `ModuleMap` can be held at this point because
// `module_resolve_callback` will be calling into `ModuleMap` from within
// the isolate.
let instantiate_result =
module.instantiate_module(tc_scope, bindings::module_resolve_callback);
if instantiate_result.is_none() {
let exception = tc_scope.exception().unwrap();
let err = exception_to_err_result(tc_scope, exception, false)
.map_err(|err| attach_handle_to_error(tc_scope, err, exception));
return err;
}
Ok(())
}
fn dynamic_import_module_evaluate(
&mut self,
load_id: ModuleLoadId,
id: ModuleId,
) -> Result<(), AnyError> {
let state_rc = Self::state(self.v8_isolate());
let module_map_rc = Self::module_map(self.v8_isolate());
let module_handle = module_map_rc
.borrow()
.get_handle(id)
.expect("ModuleInfo not found");
let status = {
let scope = &mut self.handle_scope();
let module = module_handle.get(scope);
module.get_status()
};
match status {
v8::ModuleStatus::Instantiated | v8::ModuleStatus::Evaluated => {}
_ => return Ok(()),
}
// IMPORTANT: Top-level-await is enabled, which means that return value
// of module evaluation is a promise.
//
// This promise is internal, and not the same one that gets returned to
// the user. We add an empty `.catch()` handler so that it does not result
// in an exception if it rejects. That will instead happen for the other
// promise if not handled by the user.
//
// For more details see:
// https://github.com/denoland/deno/issues/4908
// https://v8.dev/features/top-level-await#module-execution-order
let scope = &mut self.handle_scope();
let module = v8::Local::new(scope, &module_handle);
let maybe_value = module.evaluate(scope);
// Update status after evaluating.
let status = module.get_status();
if let Some(value) = maybe_value {
assert!(
status == v8::ModuleStatus::Evaluated
|| status == v8::ModuleStatus::Errored
);
let promise = v8::Local::<v8::Promise>::try_from(value)
.expect("Expected to get promise as module evaluation result");
let empty_fn = |_scope: &mut v8::HandleScope,
_args: v8::FunctionCallbackArguments,
_rv: v8::ReturnValue| {};
let empty_fn = v8::FunctionTemplate::new(scope, empty_fn);
let empty_fn = empty_fn.get_function(scope).unwrap();
promise.catch(scope, empty_fn);
let mut state = state_rc.borrow_mut();
let promise_global = v8::Global::new(scope, promise);
let module_global = v8::Global::new(scope, module);
let dyn_import_mod_evaluate = DynImportModEvaluate {
load_id,
module_id: id,
promise: promise_global,
module: module_global,
};
state.pending_dyn_mod_evaluate.push(dyn_import_mod_evaluate);
} else {
assert!(status == v8::ModuleStatus::Errored);
}
Ok(())
}
// TODO(bartlomieju): make it return `ModuleEvaluationFuture`?
/// Evaluates an already instantiated ES module.
///
/// Returns a receiver handle that resolves when module promise resolves.
/// Implementors must manually call `run_event_loop()` to drive module
/// evaluation future.
///
/// `AnyError` can be downcast to a type that exposes additional information
/// about the V8 exception. By default this type is `JsError`, however it may
/// be a different type if `RuntimeOptions::js_error_create_fn` has been set.
///
/// This function panics if module has not been instantiated.
pub fn mod_evaluate(
&mut self,
id: ModuleId,
) -> oneshot::Receiver<Result<(), AnyError>> {
let state_rc = Self::state(self.v8_isolate());
let module_map_rc = Self::module_map(self.v8_isolate());
let scope = &mut self.handle_scope();
let module = module_map_rc
.borrow()
.get_handle(id)
.map(|handle| v8::Local::new(scope, handle))
.expect("ModuleInfo not found");
let mut status = module.get_status();
assert_eq!(status, v8::ModuleStatus::Instantiated);
let (sender, receiver) = oneshot::channel();
// IMPORTANT: Top-level-await is enabled, which means that return value
// of module evaluation is a promise.
//
// Because that promise is created internally by V8, when error occurs during
// module evaluation the promise is rejected, and since the promise has no rejection
// handler it will result in call to `bindings::promise_reject_callback` adding
// the promise to pending promise rejection table - meaning JsRuntime will return
// error on next poll().
//
// This situation is not desirable as we want to manually return error at the
// end of this function to handle it further. It means we need to manually
// remove this promise from pending promise rejection table.
//
// For more details see:
// https://github.com/denoland/deno/issues/4908
// https://v8.dev/features/top-level-await#module-execution-order
let maybe_value = module.evaluate(scope);
// Update status after evaluating.
status = module.get_status();
if let Some(value) = maybe_value {
assert!(
status == v8::ModuleStatus::Evaluated
|| status == v8::ModuleStatus::Errored
);
let promise = v8::Local::<v8::Promise>::try_from(value)
.expect("Expected to get promise as module evaluation result");
let promise_global = v8::Global::new(scope, promise);
let mut state = state_rc.borrow_mut();
state.pending_promise_exceptions.remove(&promise_global);
let promise_global = v8::Global::new(scope, promise);
assert!(
state.pending_mod_evaluate.is_none(),
"There is already pending top level module evaluation"
);
state.pending_mod_evaluate = Some(ModEvaluate {
promise: promise_global,
sender,
});
scope.perform_microtask_checkpoint();
} else {
assert!(status == v8::ModuleStatus::Errored);
}
receiver
}
fn dynamic_import_reject(&mut self, id: ModuleLoadId, err: AnyError) {
let module_map_rc = Self::module_map(self.v8_isolate());
let scope = &mut self.handle_scope();
let resolver_handle = module_map_rc
.borrow_mut()
.dynamic_import_map
.remove(&id)
.expect("Invalid dynamic import id");
let resolver = resolver_handle.get(scope);
let exception = err
.downcast_ref::<ErrWithV8Handle>()
.map(|err| err.get_handle(scope))
.unwrap_or_else(|| {
let message = err.to_string();
let message = v8::String::new(scope, &message).unwrap();
v8::Exception::type_error(scope, message)
});
// IMPORTANT: No borrows to `ModuleMap` can be held at this point because
// rejecting the promise might initiate another `import()` which will
// in turn call `bindings::host_import_module_dynamically_callback` which
// will reach into `ModuleMap` from within the isolate.
resolver.reject(scope, exception).unwrap();
scope.perform_microtask_checkpoint();
}
fn dynamic_import_resolve(&mut self, id: ModuleLoadId, mod_id: ModuleId) {
let state_rc = Self::state(self.v8_isolate());
let module_map_rc = Self::module_map(self.v8_isolate());
let scope = &mut self.handle_scope();
let resolver_handle = module_map_rc
.borrow_mut()
.dynamic_import_map
.remove(&id)
.expect("Invalid dynamic import id");
let resolver = resolver_handle.get(scope);
let module = {
module_map_rc
.borrow()
.get_handle(mod_id)
.map(|handle| v8::Local::new(scope, handle))
.expect("Dyn import module info not found")
};
// Resolution success
assert_eq!(module.get_status(), v8::ModuleStatus::Evaluated);
// IMPORTANT: No borrows to `ModuleMap` can be held at this point because
// resolving the promise might initiate another `import()` which will
// in turn call `bindings::host_import_module_dynamically_callback` which
// will reach into `ModuleMap` from within the isolate.
let module_namespace = module.get_module_namespace();
resolver.resolve(scope, module_namespace).unwrap();
state_rc.borrow_mut().dyn_module_evaluate_idle_counter = 0;
scope.perform_microtask_checkpoint();
}
fn prepare_dyn_imports(
&mut self,
cx: &mut Context,
) -> Poll<Result<(), AnyError>> {
let module_map_rc = Self::module_map(self.v8_isolate());
if module_map_rc.borrow().preparing_dynamic_imports.is_empty() {
return Poll::Ready(Ok(()));
}
loop {
let poll_result = module_map_rc
.borrow_mut()
.preparing_dynamic_imports
.poll_next_unpin(cx);
if let Poll::Ready(Some(prepare_poll)) = poll_result {
let dyn_import_id = prepare_poll.0;
let prepare_result = prepare_poll.1;
match prepare_result {
Ok(load) => {
module_map_rc
.borrow_mut()
.pending_dynamic_imports
.push(load.into_future());
}
Err(err) => {
self.dynamic_import_reject(dyn_import_id, err);
}
}
// Continue polling for more prepared dynamic imports.
continue;
}
// There are no active dynamic import loads, or none are ready.
return Poll::Ready(Ok(()));
}
}
fn poll_dyn_imports(
&mut self,
cx: &mut Context,
) -> Poll<Result<(), AnyError>> {
let module_map_rc = Self::module_map(self.v8_isolate());
if module_map_rc.borrow().pending_dynamic_imports.is_empty() {
return Poll::Ready(Ok(()));
}
loop {
let poll_result = module_map_rc
.borrow_mut()
.pending_dynamic_imports
.poll_next_unpin(cx);
if let Poll::Ready(Some(load_stream_poll)) = poll_result {
let maybe_result = load_stream_poll.0;
let mut load = load_stream_poll.1;
let dyn_import_id = load.id;
if let Some(load_stream_result) = maybe_result {
match load_stream_result {
Ok(info) => {
// A module (not necessarily the one dynamically imported) has been
// fetched. Create and register it, and if successful, poll for the
// next recursive-load event related to this dynamic import.
let register_result =
load.register_and_recurse(&mut self.handle_scope(), &info);
match register_result {
Ok(()) => {
// Keep importing until it's fully drained
module_map_rc
.borrow_mut()
.pending_dynamic_imports
.push(load.into_future());
}
Err(err) => self.dynamic_import_reject(dyn_import_id, err),
}
}
Err(err) => {
// A non-javascript error occurred; this could be due to a an invalid
// module specifier, or a problem with the source map, or a failure
// to fetch the module source code.
self.dynamic_import_reject(dyn_import_id, err)
}
}
} else {
// The top-level module from a dynamic import has been instantiated.
// Load is done.
let module_id =
load.root_module_id.expect("Root module should be loaded");
let result = self.instantiate_module(module_id);
if let Err(err) = result {
self.dynamic_import_reject(dyn_import_id, err);
}
self.dynamic_import_module_evaluate(dyn_import_id, module_id)?;
}
// Continue polling for more ready dynamic imports.
continue;
}
// There are no active dynamic import loads, or none are ready.
return Poll::Ready(Ok(()));
}
}
/// "deno_core" runs V8 with Top Level Await enabled. It means that each
/// module evaluation returns a promise from V8.
/// Feature docs: https://v8.dev/features/top-level-await
///
/// This promise resolves after all dependent modules have also
/// resolved. Each dependent module may perform calls to "import()" and APIs
/// using async ops will add futures to the runtime's event loop.
/// It means that the promise returned from module evaluation will
/// resolve only after all futures in the event loop are done.
///
/// Thus during turn of event loop we need to check if V8 has
/// resolved or rejected the promise. If the promise is still pending
/// then another turn of event loop must be performed.
fn evaluate_pending_module(&mut self) {
let state_rc = Self::state(self.v8_isolate());
let maybe_module_evaluation =
state_rc.borrow_mut().pending_mod_evaluate.take();
if maybe_module_evaluation.is_none() {
return;
}
let module_evaluation = maybe_module_evaluation.unwrap();
let scope = &mut self.handle_scope();
let promise = module_evaluation.promise.get(scope);
let promise_state = promise.state();
match promise_state {
v8::PromiseState::Pending => {
// NOTE: `poll_event_loop` will decide if
// runtime would be woken soon
state_rc.borrow_mut().pending_mod_evaluate = Some(module_evaluation);
}
v8::PromiseState::Fulfilled => {
scope.perform_microtask_checkpoint();
// Receiver end might have been already dropped, ignore the result
let _ = module_evaluation.sender.send(Ok(()));
}
v8::PromiseState::Rejected => {
let exception = promise.result(scope);
scope.perform_microtask_checkpoint();
let err1 = exception_to_err_result::<()>(scope, exception, false)
.map_err(|err| attach_handle_to_error(scope, err, exception))
.unwrap_err();
// Receiver end might have been already dropped, ignore the result
let _ = module_evaluation.sender.send(Err(err1));
}
}
}
fn evaluate_dyn_imports(&mut self) {
let state_rc = Self::state(self.v8_isolate());
let mut still_pending = vec![];
let pending =
std::mem::take(&mut state_rc.borrow_mut().pending_dyn_mod_evaluate);
for pending_dyn_evaluate in pending {
let maybe_result = {
let scope = &mut self.handle_scope();
let module_id = pending_dyn_evaluate.module_id;
let promise = pending_dyn_evaluate.promise.get(scope);
let _module = pending_dyn_evaluate.module.get(scope);
let promise_state = promise.state();
match promise_state {
v8::PromiseState::Pending => {
still_pending.push(pending_dyn_evaluate);
None
}
v8::PromiseState::Fulfilled => {
Some(Ok((pending_dyn_evaluate.load_id, module_id)))
}
v8::PromiseState::Rejected => {
let exception = promise.result(scope);
let err1 = exception_to_err_result::<()>(scope, exception, false)
.map_err(|err| attach_handle_to_error(scope, err, exception))
.unwrap_err();
Some(Err((pending_dyn_evaluate.load_id, err1)))
}
}
};
if let Some(result) = maybe_result {
match result {
Ok((dyn_import_id, module_id)) => {
self.dynamic_import_resolve(dyn_import_id, module_id);
}
Err((dyn_import_id, err1)) => {
self.dynamic_import_reject(dyn_import_id, err1);
}
}
}
}
state_rc.borrow_mut().pending_dyn_mod_evaluate = still_pending;
}
/// Asynchronously load specified module and all of its dependencies.
///
/// The module will be marked as "main", and because of that
/// "import.meta.main" will return true when checked inside that module.
///
/// User must call `JsRuntime::mod_evaluate` with returned `ModuleId`
/// manually after load is finished.
pub async fn load_main_module(
&mut self,
specifier: &ModuleSpecifier,
code: Option<String>,
) -> Result<ModuleId, AnyError> {
let module_map_rc = Self::module_map(self.v8_isolate());
if let Some(code) = code {
module_map_rc.borrow_mut().new_module(
&mut self.handle_scope(),
// main module
true,
specifier.as_str(),
&code,
)?;
}
let mut load =
ModuleMap::load_main(module_map_rc.clone(), specifier.as_str()).await?;
while let Some(info_result) = load.next().await {
let info = info_result?;
let scope = &mut self.handle_scope();
load.register_and_recurse(scope, &info)?;
}
let root_id = load.root_module_id.expect("Root module should be loaded");
self.instantiate_module(root_id)?;
Ok(root_id)
}
/// Asynchronously load specified ES module and all of its dependencies.
///
/// This method is meant to be used when loading some utility code that
/// might be later imported by the main module (ie. an entry point module).
///
/// User must call `JsRuntime::mod_evaluate` with returned `ModuleId`
/// manually after load is finished.
pub async fn load_side_module(
&mut self,
specifier: &ModuleSpecifier,
code: Option<String>,
) -> Result<ModuleId, AnyError> {
let module_map_rc = Self::module_map(self.v8_isolate());
if let Some(code) = code {
module_map_rc.borrow_mut().new_module(
&mut self.handle_scope(),
// not main module
false,
specifier.as_str(),
&code,
)?;
}
let mut load =
ModuleMap::load_side(module_map_rc.clone(), specifier.as_str()).await?;
while let Some(info_result) = load.next().await {
let info = info_result?;
let scope = &mut self.handle_scope();
load.register_and_recurse(scope, &info)?;
}
let root_id = load.root_module_id.expect("Root module should be loaded");
self.instantiate_module(root_id)?;
Ok(root_id)
}
fn poll_pending_ops(
&mut self,
cx: &mut Context,
) -> Vec<(PromiseId, OpResult)> {
let state_rc = Self::state(self.v8_isolate());
let mut async_responses: Vec<(PromiseId, OpResult)> = Vec::new();
let mut state = state_rc.borrow_mut();
// Now handle actual ops.
state.have_unpolled_ops = false;
loop {
let pending_r = state.pending_ops.poll_next_unpin(cx);
match pending_r {
Poll::Ready(None) => break,
Poll::Pending => break,
Poll::Ready(Some((promise_id, resp))) => {
async_responses.push((promise_id, resp));
}
};
}
loop {
let unref_r = state.pending_unref_ops.poll_next_unpin(cx);
match unref_r {
Poll::Ready(None) => break,
Poll::Pending => break,
Poll::Ready(Some((promise_id, resp))) => {
async_responses.push((promise_id, resp));
}
};
}
async_responses
}
fn check_promise_exceptions(&mut self) -> Result<(), AnyError> {
let state_rc = Self::state(self.v8_isolate());
let mut state = state_rc.borrow_mut();
if state.pending_promise_exceptions.is_empty() {
return Ok(());
}
let key = {
state
.pending_promise_exceptions
.keys()
.next()
.unwrap()
.clone()
};
let handle = state.pending_promise_exceptions.remove(&key).unwrap();
drop(state);
let scope = &mut self.handle_scope();
let exception = v8::Local::new(scope, handle);
exception_to_err_result(scope, exception, true)
}
// Send finished responses to JS
fn async_op_response(
&mut self,
async_responses: Vec<(PromiseId, OpResult)>,
) -> Result<(), AnyError> {
let state_rc = Self::state(self.v8_isolate());
let async_responses_size = async_responses.len();
if async_responses_size == 0 {
return Ok(());
}
let js_recv_cb_handle = state_rc.borrow().js_recv_cb.clone().unwrap();
let scope = &mut self.handle_scope();
// We return async responses to JS in unbounded batches (may change),
// each batch is a flat vector of tuples:
// `[promise_id1, op_result1, promise_id2, op_result2, ...]`
// promise_id is a simple integer, op_result is an ops::OpResult
// which contains a value OR an error, encoded as a tuple.
// This batch is received in JS via the special `arguments` variable
// and then each tuple is used to resolve or reject promises
let mut args: Vec<v8::Local<v8::Value>> =
Vec::with_capacity(2 * async_responses_size);
for overflown_response in async_responses {
let (promise_id, resp) = overflown_response;
args.push(v8::Integer::new(scope, promise_id as i32).into());
args.push(resp.to_v8(scope).unwrap());
}
let tc_scope = &mut v8::TryCatch::new(scope);
let js_recv_cb = js_recv_cb_handle.get(tc_scope);
let this = v8::undefined(tc_scope).into();
js_recv_cb.call(tc_scope, this, args.as_slice());
match tc_scope.exception() {
None => Ok(()),
Some(exception) => exception_to_err_result(tc_scope, exception, false),
}
}
fn drain_macrotasks(&mut self) -> Result<(), AnyError> {
let js_macrotask_cb_handle =
match &Self::state(self.v8_isolate()).borrow().js_macrotask_cb {
Some(handle) => handle.clone(),
None => return Ok(()),
};
let scope = &mut self.handle_scope();
let js_macrotask_cb = js_macrotask_cb_handle.get(scope);
// Repeatedly invoke macrotask callback until it returns true (done),
// such that ready microtasks would be automatically run before
// next macrotask is processed.
let tc_scope = &mut v8::TryCatch::new(scope);
let this = v8::undefined(tc_scope).into();
loop {
let is_done = js_macrotask_cb.call(tc_scope, this, &[]);
if let Some(exception) = tc_scope.exception() {
return exception_to_err_result(tc_scope, exception, false);
}
let is_done = is_done.unwrap();
if is_done.is_true() {
break;
}
}
Ok(())
}
}
#[cfg(test)]
pub mod tests {
use super::*;
use crate::error::custom_error;
use crate::modules::ModuleSourceFuture;
use crate::op_sync;
use crate::ZeroCopyBuf;
use futures::future::lazy;
use std::ops::FnOnce;
use std::rc::Rc;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
pub fn run_in_task<F>(f: F)
where
F: FnOnce(&mut Context) + Send + 'static,
{
futures::executor::block_on(lazy(move |cx| f(cx)));
}
enum Mode {
Async,
AsyncZeroCopy(bool),
}
struct TestState {
mode: Mode,
dispatch_count: Arc<AtomicUsize>,
}
fn dispatch(rc_op_state: Rc<RefCell<OpState>>, payload: OpPayload) -> Op {
let rc_op_state2 = rc_op_state.clone();
let op_state_ = rc_op_state2.borrow();
let test_state = op_state_.borrow::<TestState>();
test_state.dispatch_count.fetch_add(1, Ordering::Relaxed);
let (control, buf): (u8, Option<ZeroCopyBuf>) =
payload.deserialize().unwrap();
match test_state.mode {
Mode::Async => {
assert_eq!(control, 42);
let resp = (0, serialize_op_result(Ok(43), rc_op_state));
Op::Async(Box::pin(futures::future::ready(resp)))
}
Mode::AsyncZeroCopy(has_buffer) => {
assert_eq!(buf.is_some(), has_buffer);
if let Some(buf) = buf {
assert_eq!(buf.len(), 1);
}
let resp = serialize_op_result(Ok(43), rc_op_state);
Op::Async(Box::pin(futures::future::ready((0, resp))))
}
}
}
fn setup(mode: Mode) -> (JsRuntime, Arc<AtomicUsize>) {
let dispatch_count = Arc::new(AtomicUsize::new(0));
let mut runtime = JsRuntime::new(Default::default());
let op_state = runtime.op_state();
op_state.borrow_mut().put(TestState {
mode,
dispatch_count: dispatch_count.clone(),
});
runtime.register_op("op_test", dispatch);
runtime.sync_ops_cache();
runtime
.execute_script(
"setup.js",
r#"
function assert(cond) {
if (!cond) {
throw Error("assert");
}
}
"#,
)
.unwrap();
assert_eq!(dispatch_count.load(Ordering::Relaxed), 0);
(runtime, dispatch_count)
}
#[test]
fn test_dispatch() {
let (mut runtime, dispatch_count) = setup(Mode::Async);
runtime
.execute_script(
"filename.js",
r#"
let control = 42;
Deno.core.opAsync("op_test", control);
async function main() {
Deno.core.opAsync("op_test", control);
}
main();
"#,
)
.unwrap();
assert_eq!(dispatch_count.load(Ordering::Relaxed), 2);
}
#[test]
fn test_dispatch_no_zero_copy_buf() {
let (mut runtime, dispatch_count) = setup(Mode::AsyncZeroCopy(false));
runtime
.execute_script(
"filename.js",
r#"
Deno.core.opAsync("op_test");
"#,
)
.unwrap();
assert_eq!(dispatch_count.load(Ordering::Relaxed), 1);
}
#[test]
fn test_dispatch_stack_zero_copy_bufs() {
let (mut runtime, dispatch_count) = setup(Mode::AsyncZeroCopy(true));
runtime
.execute_script(
"filename.js",
r#"
let zero_copy_a = new Uint8Array([0]);
Deno.core.opAsync("op_test", null, zero_copy_a);
"#,
)
.unwrap();
assert_eq!(dispatch_count.load(Ordering::Relaxed), 1);
}
#[test]
fn test_execute_script_return_value() {
let mut runtime = JsRuntime::new(Default::default());
let value_global = runtime.execute_script("a.js", "a = 1 + 2").unwrap();
{
let scope = &mut runtime.handle_scope();
let value = value_global.get(scope);
assert_eq!(value.integer_value(scope).unwrap(), 3);
}
let value_global = runtime.execute_script("b.js", "b = 'foobar'").unwrap();
{
let scope = &mut runtime.handle_scope();
let value = value_global.get(scope);
assert!(value.is_string());
assert_eq!(
value.to_string(scope).unwrap().to_rust_string_lossy(scope),
"foobar"
);
}
}
#[tokio::test]
async fn test_resolve_value() {
let mut runtime = JsRuntime::new(Default::default());
let value_global = runtime
.execute_script("a.js", "Promise.resolve(1 + 2)")
.unwrap();
let result_global = runtime.resolve_value(value_global).await.unwrap();
{
let scope = &mut runtime.handle_scope();
let value = result_global.get(scope);
assert_eq!(value.integer_value(scope).unwrap(), 3);
}
let value_global = runtime
.execute_script(
"a.js",
"Promise.resolve(new Promise(resolve => resolve(2 + 2)))",
)
.unwrap();
let result_global = runtime.resolve_value(value_global).await.unwrap();
{
let scope = &mut runtime.handle_scope();
let value = result_global.get(scope);
assert_eq!(value.integer_value(scope).unwrap(), 4);
}
let value_global = runtime
.execute_script("a.js", "Promise.reject(new Error('fail'))")
.unwrap();
let err = runtime.resolve_value(value_global).await.unwrap_err();
assert_eq!(
"Uncaught Error: fail",
err.downcast::<JsError>().unwrap().message
);
let value_global = runtime
.execute_script("a.js", "new Promise(resolve => {})")
.unwrap();
let error_string = runtime
.resolve_value(value_global)
.await
.unwrap_err()
.to_string();
assert_eq!(
"Promise resolution is still pending but the event loop has already resolved.",
error_string,
);
}
#[test]
fn terminate_execution() {
let (mut isolate, _dispatch_count) = setup(Mode::Async);
// TODO(piscisaureus): in rusty_v8, the `thread_safe_handle()` method
// should not require a mutable reference to `struct rusty_v8::Isolate`.
let v8_isolate_handle = isolate.v8_isolate().thread_safe_handle();
let terminator_thread = std::thread::spawn(move || {
// allow deno to boot and run
std::thread::sleep(std::time::Duration::from_millis(100));
// terminate execution
let ok = v8_isolate_handle.terminate_execution();
assert!(ok);
});
// Rn an infinite loop, which should be terminated.
match isolate.execute_script("infinite_loop.js", "for(;;) {}") {
Ok(_) => panic!("execution should be terminated"),
Err(e) => {
assert_eq!(e.to_string(), "Uncaught Error: execution terminated")
}
};
// Cancel the execution-terminating exception in order to allow script
// execution again.
let ok = isolate.v8_isolate().cancel_terminate_execution();
assert!(ok);
// Verify that the isolate usable again.
isolate
.execute_script("simple.js", "1 + 1")
.expect("execution should be possible again");
terminator_thread.join().unwrap();
}
#[test]
fn dangling_shared_isolate() {
let v8_isolate_handle = {
// isolate is dropped at the end of this block
let (mut runtime, _dispatch_count) = setup(Mode::Async);
// TODO(piscisaureus): in rusty_v8, the `thread_safe_handle()` method
// should not require a mutable reference to `struct rusty_v8::Isolate`.
runtime.v8_isolate().thread_safe_handle()
};
// this should not SEGFAULT
v8_isolate_handle.terminate_execution();
}
#[test]
fn test_pre_dispatch() {
run_in_task(|mut cx| {
let (mut runtime, _dispatch_count) = setup(Mode::Async);
runtime
.execute_script(
"bad_op_id.js",
r#"
let thrown;
try {
Deno.core.opSync(100);
} catch (e) {
thrown = e;
}
assert(String(thrown) === "TypeError: Unknown op id: 100");
"#,
)
.unwrap();
if let Poll::Ready(Err(_)) = runtime.poll_event_loop(&mut cx, false) {
unreachable!();
}
});
}
#[test]
fn syntax_error() {
let mut runtime = JsRuntime::new(Default::default());
let src = "hocuspocus(";
let r = runtime.execute_script("i.js", src);
let e = r.unwrap_err();
let js_error = e.downcast::<JsError>().unwrap();
assert_eq!(js_error.end_column, Some(11));
}
#[test]
fn test_encode_decode() {
run_in_task(|mut cx| {
let (mut runtime, _dispatch_count) = setup(Mode::Async);
runtime
.execute_script(
"encode_decode_test.js",
include_str!("encode_decode_test.js"),
)
.unwrap();
if let Poll::Ready(Err(_)) = runtime.poll_event_loop(&mut cx, false) {
unreachable!();
}
});
}
#[test]
fn test_serialize_deserialize() {
run_in_task(|mut cx| {
let (mut runtime, _dispatch_count) = setup(Mode::Async);
runtime
.execute_script(
"serialize_deserialize_test.js",
include_str!("serialize_deserialize_test.js"),
)
.unwrap();
if let Poll::Ready(Err(_)) = runtime.poll_event_loop(&mut cx, false) {
unreachable!();
}
});
}
#[test]
fn test_error_builder() {
fn op_err(
_: &mut OpState,
_: (),
_: Option<ZeroCopyBuf>,
) -> Result<(), AnyError> {
Err(custom_error("DOMExceptionOperationError", "abc"))
}
pub fn get_error_class_name(_: &AnyError) -> &'static str {
"DOMExceptionOperationError"
}
run_in_task(|mut cx| {
let mut runtime = JsRuntime::new(RuntimeOptions {
get_error_class_fn: Some(&get_error_class_name),
..Default::default()
});
runtime.register_op("op_err", op_sync(op_err));
runtime.sync_ops_cache();
runtime
.execute_script(
"error_builder_test.js",
include_str!("error_builder_test.js"),
)
.unwrap();
if let Poll::Ready(Err(_)) = runtime.poll_event_loop(&mut cx, false) {
unreachable!();
}
});
}
#[test]
fn will_snapshot() {
let snapshot = {
let mut runtime = JsRuntime::new(RuntimeOptions {
will_snapshot: true,
..Default::default()
});
runtime.execute_script("a.js", "a = 1 + 2").unwrap();
runtime.snapshot()
};
let snapshot = Snapshot::JustCreated(snapshot);
let mut runtime2 = JsRuntime::new(RuntimeOptions {
startup_snapshot: Some(snapshot),
..Default::default()
});
runtime2
.execute_script("check.js", "if (a != 3) throw Error('x')")
.unwrap();
}
#[test]
fn test_from_boxed_snapshot() {
let snapshot = {
let mut runtime = JsRuntime::new(RuntimeOptions {
will_snapshot: true,
..Default::default()
});
runtime.execute_script("a.js", "a = 1 + 2").unwrap();
let snap: &[u8] = &*runtime.snapshot();
Vec::from(snap).into_boxed_slice()
};
let snapshot = Snapshot::Boxed(snapshot);
let mut runtime2 = JsRuntime::new(RuntimeOptions {
startup_snapshot: Some(snapshot),
..Default::default()
});
runtime2
.execute_script("check.js", "if (a != 3) throw Error('x')")
.unwrap();
}
#[test]
fn test_heap_limits() {
let create_params =
v8::Isolate::create_params().heap_limits(0, 3 * 1024 * 1024);
let mut runtime = JsRuntime::new(RuntimeOptions {
create_params: Some(create_params),
..Default::default()
});
let cb_handle = runtime.v8_isolate().thread_safe_handle();
let callback_invoke_count = Rc::new(AtomicUsize::default());
let inner_invoke_count = Rc::clone(&callback_invoke_count);
runtime.add_near_heap_limit_callback(
move |current_limit, _initial_limit| {
inner_invoke_count.fetch_add(1, Ordering::SeqCst);
cb_handle.terminate_execution();
current_limit * 2
},
);
let err = runtime
.execute_script(
"script name",
r#"let s = ""; while(true) { s += "Hello"; }"#,
)
.expect_err("script should fail");
assert_eq!(
"Uncaught Error: execution terminated",
err.downcast::<JsError>().unwrap().message
);
assert!(callback_invoke_count.load(Ordering::SeqCst) > 0)
}
#[test]
fn test_heap_limit_cb_remove() {
let mut runtime = JsRuntime::new(Default::default());
runtime.add_near_heap_limit_callback(|current_limit, _initial_limit| {
current_limit * 2
});
runtime.remove_near_heap_limit_callback(3 * 1024 * 1024);
assert!(runtime.allocations.near_heap_limit_callback_data.is_none());
}
#[test]
fn test_heap_limit_cb_multiple() {
let create_params =
v8::Isolate::create_params().heap_limits(0, 3 * 1024 * 1024);
let mut runtime = JsRuntime::new(RuntimeOptions {
create_params: Some(create_params),
..Default::default()
});
let cb_handle = runtime.v8_isolate().thread_safe_handle();
let callback_invoke_count_first = Rc::new(AtomicUsize::default());
let inner_invoke_count_first = Rc::clone(&callback_invoke_count_first);
runtime.add_near_heap_limit_callback(
move |current_limit, _initial_limit| {
inner_invoke_count_first.fetch_add(1, Ordering::SeqCst);
current_limit * 2
},
);
let callback_invoke_count_second = Rc::new(AtomicUsize::default());
let inner_invoke_count_second = Rc::clone(&callback_invoke_count_second);
runtime.add_near_heap_limit_callback(
move |current_limit, _initial_limit| {
inner_invoke_count_second.fetch_add(1, Ordering::SeqCst);
cb_handle.terminate_execution();
current_limit * 2
},
);
let err = runtime
.execute_script(
"script name",
r#"let s = ""; while(true) { s += "Hello"; }"#,
)
.expect_err("script should fail");
assert_eq!(
"Uncaught Error: execution terminated",
err.downcast::<JsError>().unwrap().message
);
assert_eq!(0, callback_invoke_count_first.load(Ordering::SeqCst));
assert!(callback_invoke_count_second.load(Ordering::SeqCst) > 0);
}
#[test]
fn es_snapshot() {
#[derive(Default)]
struct ModsLoader;
impl ModuleLoader for ModsLoader {
fn resolve(
&self,
specifier: &str,
referrer: &str,
_is_main: bool,
) -> Result<ModuleSpecifier, AnyError> {
assert_eq!(specifier, "file:///main.js");
assert_eq!(referrer, ".");
let s = crate::resolve_import(specifier, referrer).unwrap();
Ok(s)
}
fn load(
&self,
_module_specifier: &ModuleSpecifier,
_maybe_referrer: Option<ModuleSpecifier>,
_is_dyn_import: bool,
) -> Pin<Box<ModuleSourceFuture>> {
unreachable!()
}
}
let loader = std::rc::Rc::new(ModsLoader::default());
let mut runtime = JsRuntime::new(RuntimeOptions {
module_loader: Some(loader),
will_snapshot: true,
..Default::default()
});
let specifier = crate::resolve_url("file:///main.js").unwrap();
let source_code = "Deno.core.print('hello\\n')".to_string();
let module_id = futures::executor::block_on(
runtime.load_main_module(&specifier, Some(source_code)),
)
.unwrap();
let _ = runtime.mod_evaluate(module_id);
futures::executor::block_on(runtime.run_event_loop(false)).unwrap();
let _snapshot = runtime.snapshot();
}
#[test]
fn test_error_without_stack() {
let mut runtime = JsRuntime::new(RuntimeOptions::default());
// SyntaxError
let result = runtime.execute_script(
"error_without_stack.js",
r#"
function main() {
console.log("asdf);
}
main();
"#,
);
let expected_error = r#"Uncaught SyntaxError: Invalid or unexpected token
at error_without_stack.js:3:14"#;
assert_eq!(result.unwrap_err().to_string(), expected_error);
}
#[test]
fn test_error_stack() {
let mut runtime = JsRuntime::new(RuntimeOptions::default());
let result = runtime.execute_script(
"error_stack.js",
r#"
function assert(cond) {
if (!cond) {
throw Error("assert");
}
}
function main() {
assert(false);
}
main();
"#,
);
let expected_error = r#"Error: assert
at assert (error_stack.js:4:11)
at main (error_stack.js:9:3)
at error_stack.js:12:1"#;
assert_eq!(result.unwrap_err().to_string(), expected_error);
}
#[test]
fn test_error_async_stack() {
run_in_task(|cx| {
let mut runtime = JsRuntime::new(RuntimeOptions::default());
runtime
.execute_script(
"error_async_stack.js",
r#"
(async () => {
const p = (async () => {
await Promise.resolve().then(() => {
throw new Error("async");
});
})();
try {
await p;
} catch (error) {
console.log(error.stack);
throw error;
}
})();"#,
)
.unwrap();
let expected_error = r#"Error: async
at error_async_stack.js:5:13
at async error_async_stack.js:4:5
at async error_async_stack.js:10:5"#;
match runtime.poll_event_loop(cx, false) {
Poll::Ready(Err(e)) => {
assert_eq!(e.to_string(), expected_error);
}
_ => panic!(),
};
})
}
#[test]
fn test_pump_message_loop() {
run_in_task(|cx| {
let mut runtime = JsRuntime::new(RuntimeOptions::default());
runtime
.execute_script(
"pump_message_loop.js",
r#"
function assertEquals(a, b) {
if (a === b) return;
throw a + " does not equal " + b;
}
const sab = new SharedArrayBuffer(16);
const i32a = new Int32Array(sab);
globalThis.resolved = false;
(function() {
const result = Atomics.waitAsync(i32a, 0, 0);
result.value.then(
(value) => { assertEquals("ok", value); globalThis.resolved = true; },
() => { assertUnreachable();
});
})();
const notify_return_value = Atomics.notify(i32a, 0, 1);
assertEquals(1, notify_return_value);
"#,
)
.unwrap();
match runtime.poll_event_loop(cx, false) {
Poll::Ready(Ok(())) => {}
_ => panic!(),
};
// noop script, will resolve promise from first script
runtime
.execute_script("pump_message_loop2.js", r#"assertEquals(1, 1);"#)
.unwrap();
// check that promise from `Atomics.waitAsync` has been resolved
runtime
.execute_script(
"pump_message_loop3.js",
r#"assertEquals(globalThis.resolved, true);"#,
)
.unwrap();
})
}
#[test]
fn test_core_js_stack_frame() {
let mut runtime = JsRuntime::new(RuntimeOptions::default());
// Call non-existent op so we get error from `core.js`
let error = runtime
.execute_script(
"core_js_stack_frame.js",
"Deno.core.opSync('non_existent');",
)
.unwrap_err();
let error_string = error.to_string();
// Test that the script specifier is a URL: `deno:<repo-relative path>`.
assert!(error_string.contains("deno:core/01_core.js"));
}
#[test]
fn test_v8_platform() {
let options = RuntimeOptions {
v8_platform: Some(v8::new_default_platform(0, false).make_shared()),
..Default::default()
};
let mut runtime = JsRuntime::new(options);
runtime.execute_script("<none>", "").unwrap();
}
}